In certain sectors, these sites are not just frowned upon, they're outright impossible to access. Most of the financial world, for example, prevents employees from using sites like Facebook, Twitter and even web-based email like Gmail, citing potential threats as well as an interruption from work as their reasoning.

"It sucks when you see employees on Facebook -- it's a distraction, including for me," says Alex Ikonn, co-founder of Luxy Hair, a company specializing in hair extentions. "But it's also a major benefit for businesses."

Ikonn would know -- his whole company was built through social media. As a former social media consultant, he was already quite familiar with Facebook, Twitter and YouTube, and now he, and his team of five employees, have built their brand through these channels, engaging over 42,000 Facebook members and 200,000 YouTube subscribers daily.

For companies like these, Facebook and Twitter are essential tools for growth. "There's always been a saying for new businesses, 'word of mouth.' But now it's 'word of mouse," says George Affleck, President and CEO of Curve Communications, a service marketing and communications agency based in Vancouver.